Quick workflow
- Choose a basemap (e.g., satellite imagery).
- Optional: Choose an overlay (IBRA, IPA, mapsheets, etc.).
- Click Place plot, then click the map where you want the plot.
- Drag the plot to move it. Use the rotation handle to rotate it.
- Use PNG (export current view) to download a map image of exactly what you are looking at.
- Use GPKG to download the plot polygon as GIS data.
- If you have georeferencing files, follow the QGIS / Avenza sections below.
Screenshots are optional. If they are not present, they will automatically be hidden.
Place & edit the plot
1) Set the plot size
In the Plot box, set Width (m) and Height (m). These are real-world metres.
2) Place the plot
- Click Place plot (click map).
- Click once on the map where you want the centre of the plot.
- The plot rectangle appears.
3) Move and rotate
- Move: drag the plot polygon.
- Rotate: use the rotation handle.
- Clear: click Clear plot to remove it.
4) Zoom to plot
Click Zoom to plot to centre the map on your plot.
Basemap & overlays
Basemap (imagery / background)
Choose the basemap you want (e.g., satellite imagery). If a basemap is slow to load, wait a few seconds before exporting.
Overlay (optional reference layers)
Overlays help you identify IBRA regions, IPAs, mapsheets, and similar boundaries. You can click inside an overlay polygon to see its name (where available).
Exports
PNG (export current view)
This button downloads a PNG image of what Leaflet is rendering right now: imagery + plot polygon + overlays (if shown).
- It does not change your zoom or map position.
- If imagery is missing in the PNG, zoom out slightly and try again.
Georeferencing files (if provided by the app)
Some versions of the app also provide small “sidecar” files for georeferencing:
- PGW — “world file” containing pixel size and origin
- PRJ — the coordinate reference system (CRS), commonly EPSG:3857 (Web Mercator)
GPKG (plot polygon)
Downloads the plot polygon as a GIS layer. You can open it in QGIS, or convert it for Avenza.
Use the export in QGIS
Open the georeferenced PNG
- Put the files in the same folder:
your_map.pngyour_map.pgwyour_map.prj
- Open QGIS.
- Go to Layer → Add Layer → Add Raster Layer…
- Select the
.pngand click Add.
Open the plot polygon (GPKG)
- Go to Layer → Add Layer → Add Vector Layer…
- Select the
.gpkgand click Add.
Make the layers line up
QGIS can automatically transform layers to match your map view.
- Go to Project → Properties → CRS.
- Set the Project CRS to EPSG:3857 (recommended for matching the PNG).
- Ensure “on-the-fly” transformation is enabled (default in modern QGIS).
13890000, -2816000.
That is still Australia — it is just in metres, not degrees.
If the PNG and polygon do not align
- Confirm the PNG’s CRS is EPSG:3857 (right-click PNG → Properties → Information).
- Confirm the GPKG is in EPSG:4326 (common) or another CRS; QGIS will reproject it.
- Make sure the PGW/PRJ file names exactly match the PNG base name.
Use the export in Avenza Maps
Recommended workflow
- First open your PNG in QGIS (see the QGIS section above).
- Create a GeoTIFF from the PNG (see the “Make a GeoTIFF” section below).
- Transfer the GeoTIFF to your phone/tablet (AirDrop, USB, cloud drive, email attachment).
- Open it in Avenza Maps:
- On iOS, you can use Share → Open in Avenza if available.
- Or in Avenza, use Import and choose the GeoTIFF file.
Add the plot polygon to Avenza (optional)
Avenza commonly imports vector overlays as KML/KMZ. If you want the plot boundary on your phone:
- In QGIS, load the plot
.gpkg. - Right-click the layer → Export → Save Features As…
- Choose Format: KML (or KMZ), and choose CRS: EPSG:4326.
- Transfer the KML/KMZ to your phone and import it into Avenza.
Make a GeoTIFF from the PNG
A GeoTIFF is a single file that contains both the image and its georeferencing. This is the most compatible format for Avenza and GIS tools.
Method A (recommended): QGIS “Save As…”
- Open the PNG in QGIS (with its PGW/PRJ in the same folder).
- Right-click the PNG layer → Export → Save As…
- Format: GeoTIFF
- CRS:
- Use EPSG:3857 to keep it exactly as Leaflet rendered it, OR
- Use EPSG:4326 if you want “lat/long degrees” (often friendlier for field apps).
- Click OK to create the GeoTIFF.
Method B (optional): GDAL command line
Only use this if you are comfortable with a terminal. (QGIS method is easier.)
If the PNG has its world file and CRS set correctly, GDAL can usually convert it directly:
gdal_translate -of GTiff your_map.png your_map.tif
If you need the output in EPSG:4326:
gdalwarp -t_srs EPSG:4326 your_map.png your_map_4326.tif
Troubleshooting
PNG has no imagery / “imagery not available” tiles
- Zoom out one step and export again.
- Wait a few seconds for imagery to load before exporting.
- Try a different basemap (some areas/providers have limited high-zoom coverage).
QGIS shows big numbers that don’t look like Australia
If the PNG is EPSG:3857 (Web Mercator), coordinates are in metres, not degrees. Australia still appears in the right place on the map.
PNG does not place correctly in QGIS
- Confirm the PNG, PGW, and PRJ names match exactly (same base name).
- If prompted, choose EPSG:3857.
- Set the Project CRS to EPSG:3857 for easiest alignment.
GeoTIFF won’t import into Avenza
- Try exporting the GeoTIFF in EPSG:4326 from QGIS (often more compatible).
- Keep the file size reasonable (very large rasters can be slow on phones).
- If you are using email, large attachments may be blocked — use AirDrop or cloud drive.